Air blast nozzle device for enrobers or chocolate coating machines and the like



Nov. 5, 1946. v A. A. TUNLEY 2,410,762

AIR BLAST NOZZLE DEVICE FOR ENROBERS OR CHOCOLATE COATING MACHINES ANDTHE LIKE Filed Oct. 19, 1945 2 Sheets-Sheet l ET Q Nov. 5, 1946. A. A.TUNLEY 2,410,762

AIR BLAST NOZZLE DEVICE FOR ENROBERS OR CHOCOLATE COATING MACHINES ANDTHE LIKE Filed Oct. 19,-1945 2 Sheets-Sheet 2 Patented Nov. 5, 1946 AIRBLAST NOZZLE DEVICE FOR ENROBERS OR CHOCOLATE CQATING MACHINES AND THELIKE Allan Ashmead Tunley, Peterhorough, England,

assignor to Baker Perkins Limited, Peterborough, Northampton, EnglandApplication October 19, 1943, Serial No. 506,894 In Great BritainSeptember 3, 1942 4 Claims.

This invention relates to enrobers or machines for coating biscuits orsweetmeats or other socalled centres with chocolate or like settingcoating.

It is customary in machines of the above kind to pass the centres upon awire mesh band conveyor under a transverse curtain of liquid chocolatefor coating or encasing the centres with a layer of chocolate, and totreat the coated centres While the chocolate is still in a plasticcondition to the action of an air blast or blasts to distribute thecoating evenly and remove surplus chocolate.

An aim of the present invention is to provide improved air blast nozzlemeans adapted to opcrate with greater efliciency than those at presentknown and to afford improved facilities for angular adjustment andregulation,

The invention consists in air blast nozzle means for enrobers,comprising two or more nozzles coupled to air supply means, and meanswhereby the direction of each nozzle may be adjusted independently ofthe other nozzle or nozzles so that the air blasts from the nozzles maybe arranged to act in the same sense or direction or at oppositelyinclined angles.

The invention also consists in providing air blast nozzle means having ahinged connection with an air supply duct (through which the airvelocity is preferably constant) for enabling the direction angle of thenozzle to be adjusted while maintaining a smooth air flow from the ductto the nozzle without any abrupt change of direction or change ofvelocity.

According to the preferred form the nozzle comprises a pair of plates orflaps hinged on a transverse axis to the air supply duct, each platebeing connected to one end of a lever, the other end of which ispivotally attached to a displaceable bar or element for manipulating thenozzle plates and adjusting them for altering the direction or angle ofthe blast. One or both of the levers may be adjustably connected to thebar or element for the purpose of enabling'the width of nozzle slot oropening to be regulated.

Double air blast nozzles have been employed hitherto. These known nozzledevices are adjustable for direction so that the angle of the air blastWith respect to the centres may be altered but in all positions the twoair streams of the pair always remain parallel. It has been found thatthese arrangements and their capacity for adjustment do not fulfilrequirements since the blasts do not act uniformly upon the travellingcentres and are liable to cause undue displacement in one direction oranother of the chocolate, which may result in the denuding of thecentres at some part or part and a local piling of the chocolateelsewhere, while certain of the sides of the centres are liable to bemasked from the air action.

It is an object of the present invention to provide air blast meansadapted to avoid the above difficulties and afford facilities forcontrolling the air blast treatment such as will ensure the desireddistribution and uniform coating of chocolate upon the centres.

With this end in View the invention consists in providin a plurality ofnozzles and means adapted to enable independent angular adjustmentthereof such that the air blasts from the nozzles may be arranged to actin the same sense or direction or at oppositely inclined angles, in ucha way that the front and rear as well as the upper surface of thecentres may be equally treatedto the air blast effect.

A further feature of the invention resides in supplying the nozzles withair in parallel through individual ducts from a main trunk or supplyline.

With a view to further improving the efficiency of the air supply forthe nozzles the invention also comprises the employment of a main trunkor supply line provided with a distribution box or hood so formed thatair passes therethrough towards the nozzles at an increasing velocity.

The. invention also comprises in combination With a distribution box orhood according to the preceding paragraph, the provision of a pair ofindependent nozzle supply ducts to each of which nozzles are connectedand so formed that the air passes from the box to the nozzles inparallel at a constant velocity.

The preferred form of distributing box comprises a pair ofair streams ofgradually decreasing area-and a streamlined surface element for dividingthe air streams and promoting a smooth flow of air at a graduallyincreasing velocity.

In the accompanying drawings:

Figure 1 is a front elevation of the improved nozzle means according tothe invention;

Figure 2 is an end elevation looking from the right in Fig. 1, and

Figure 3 is a section on the line 3-3 of Fig. 1 showing certain detailsof construction of the nozzles. V

In carrying the invention into efiect according to one mode as describedby way of example, the fan for providing the air supply for the nozzlesis connected by a conduit I to a distributing box or casing 2 which incross section (Figure 1, i. e. a section transverse of the enrobermachine) is of truncated triangular shape with the base downwards, whilein a section at rightangles (Figure 2) the outline is also of truncatedtriangular shape but with the base upward. The walls of the box orcasing may be of sheet metal and in the centre of the box disposedsymmetrically about the axis of the inflow of air from the fan is asurface element obstruction 3 which extends between the front and backwalls 4 and 5 of the box so as to divide the air delivered by the faninto two equal streams 8 and I. The obstruction 3 may be formed bycurved plate members connected together to form a body of roughlyelliptical shape in cross section with tapering upper and lower ends togive a streamlining efiect, while the curvature of the plates is suchthat in conjunction with the outer side walls 8 and S of the box the airpassages as viewed.

in cross-section of the machine are of gradually increasing dimensionsto distribute the air flow evenly towards the nozzle means hereinafterdescribed, which extend across the full width of the wire conveyor bandfor the centres to be treated. The obstruction plates terminate short ofthe delivery from the box so that the air streams merge or adjointhereat.

The angle of the downwardly converging front and back walls 4 and 5 ofthe box 2 are so arranged that despite the increasing width of the airstream passages the cross-sectional area of the air streams graduallydecreases from the supply entrance to the delivery towards the nozzlemeans. The distributing box 2 at the bottom or the delivery side is ofrectangular shape in plan and afiords a transversely elongated deliveryslot or mouth I to which is attached a pair of parallel-walled air ductsII, I2 which diverge outwardly as seen in Fig. 2, and present the aspectof a breeches pipe. The area of these ducts II and I2 is constantthroughout, the arrangement being such that the air entering the box. 2from the fan is divided first into two streams of gradually decreasingarea so that gradually increasing air velocity is afiorded, and theneach stream is again divided as it passes into' the breeches ducts IIand i2 and travels therethrough at a uniform velocity.

The lower ends of the breeches ducts have mounted thereon a horizontalplate I3 below which the nozzles are mounted. At the outer ends of thehorizontal plates depending side plates I4, I are secured between whichthe nozzle forming plates hereinafter described are located and thesedependin plates I4, I5 serve to form a closure for the ends of thenozzleforming plates so that they provide air blast deliveries acrossthe full Width of the conveyor band for the centres. The dependingplates also form a convenient mounting for the rods or spindles by meansof which the nozzle-forming plates are hinged to the horizontal plateatlthe delivery ends of the breeches ducts.

The nozzle-forming plates for the breeches ducts I I and I2 arecounterparts one of the other so that the description thereof can beconveniently confined to the arrangements for one of the legs orbranches of the breeches ducts.

The nozzle is formed by a pair of plates I6 and I1 each of which issecured around one of the bars or spindles I8 referred to above whichlie parallel to oneanother and are mounted in slots I9 in the closureplates I4, I5. The bars or ably mounted in the slots I9 of the closureplates and the underside of the horizontal plate I3 is provided with alayer of felt 29 against which the curls of the plates I6, I! are beddedso that an air seal is afiorded. The spindles I8 at one end convenientlyproject through the closure plate !5 so that they may receive means forcontrolling and adjusting the angular position of the nozzle plates I6,I'I. These control means may comprise a pair of upwardly extendinglevers 2I, 22 each of which is secured to the projecting end of ahinging bar or spindle I8 and pivotally connected at its upper end to ahorizontal manipulating link or bar 23. The pivotal connection of thelever 2I of one of the nozzle plates may be secured to the manipulatinglink 23 by a slot and thumb screw connection 24, 25 so as to enable itsnozzle plate I6 to be angularly adjusted with respect to the othernozzle plate I7 in order to alter the width of nozzle openin 26.

The tightening of the thumb screw 25 against the link also operates bythe gripping action to hold the nozzle plates I6, I! in their adjustedangular positions relatively to the breeches ducts II, I2.

One of the levers 2! of the pair may have a downward extension 2'!located between a pair of stops 23 provided on the adjacent closureplate I5 so as to limit the displacement of the manipulating piece andconsequently the range of angular adjustment of the nozzle. Below theair outlet from the nozzles and spaced therefrom a deflector 29 in theform of a flared channel plate is slun on a pair of end links 30rotatably mounted upon one of the hinging spindles I8 for the nozzleflaps Iii, N. This deflector plate 29 when the nozzles are in operationis swung about its pivot out of the way of the air blast while to cutoff the blast quickly it is dropped into position below the nozzle todeflect the air streams. According to one arrangement the deflector 29is interlocked with the clutch through which the drive to the wire bandcarrying the centres is communicated, so that when this clutch isdisengaged the deflector is dropped into position to obstruct the airblast issuing from the nozzles according to a known arrangement.

It will be appreciated from the above that the pairs of flaps I6, I!constituting the two nozzles can be turned about their pivotal axes orspindles I8 independently to vary the angle of direction of the airblasts as desired. For example, by operation of the manipulating links23 the two nozzles can be disposed so that the air blasts converge ormeet or they can be turned by the manipulating links so that the airblasts diverge or are directed in an opposite sense or direction. Theflaps I6, H on operation of the manipulating link 23 for each nozzle,move together for directional displacement. If it is required to adjustthe width of a nozzle opening the adjustable lever 2I of a pair iangularly adjusted to move the edge of its flap I 6 nearer to or furtherfrom the other flap edge by loosening the thumb screw 25 on themanipulating link and resetting the pivot end of the lever in the slot24 and tightening up the screw in the new position.

In operation, assuming that the nozzles IS, H are adjusted to giveconverging air blasts, the centres on the Wire band as they arrive underthe nozzles will first receive an air blast operating upon the front andtop of the centre, while as the centre proceeds it will receive a blastdirected at spindles- I 8 carrying the nozzles plates are rotat- 76 anoppositely inclined angle upon the upper surface of the centre and uponthe rear side of the centre. If the nozzles I6, I1 are adjusted toafford diverging air blasts the centres similarly receive air directedagainst the top surface thereof and angles, each of said nozzlescomprising a pair of plates hinged on transverse axes, each plate beingrigidly connected to one end of a lever, the other ends of said leversbeing pivotally attached to a displaceable bar for manipulating theplates and adjusting them for altering the angle of the blast, one ofsaid levers being adjustably connected to said bar for enabling theopening of the nozzle to be varied, said plates being secured in theiradjusted position by a friction grip applied between one of said leversand the manipulating bar.

2. Apparatus for treating chocolate or like coated goods in an enroberto an air blast formed by two contiguous air streams comprising twojuxtaposed air blast nozzles arranged in series, air suppply means towhich said nozzles are connected, and means for adjusting the directionof each nozzle independently of the other, whereby the air blasts fromthe nozzles may be arranged to act in the same direction or atoppositely inclined angles, each of said nozzles comprising a pair ofplates secured upon spindles pivotally mounted in end closure plates,levers mounted on said spindles atone end thereof, the free ends of thelevers being operatively connected to a displaceable bar formanipulating the plates and adjusting them for altering the angle of theblast, one of said levers having an extension moving between stops on anend closure plate.

3. Apparatus for treating chocolate or like coated goods in an enroberto an air blast formed by two contiguous air streams comprising two juXtaposed air blast nozzles arranged in series, air supply means to whichsaid nozzles are connected, and means for adjusting the direction ofeach nozzle independently of the other, whereby the air blasts from thenozzles may be arranged to act in the same direction or at oppositelyinclined angles, said nozzles being coupled to individual ducts from amain supply trunk whereby they are supplied in parallel and wherein themain supply trunk comprises a distribution hood having a streamlinedsurface element dividing the air stream into a pair of air streams ofgradually decreasing area, and promoting a smooth flow of air at agradually increasing velocity.

4. Air blast nozzle means for an enrober comprising an air supply duct,a nozzle coupled to said duct and comprising a pair of plates hinged tosaid duct on spaced transverse axes, each plate being rigidly connectedto one end of a lever, the other ends of said levers being pivotallyattached to a displaceable bar for manipulating the plates and adjustingthem for altering the direction of the angle of the blast, said leversbeing adjustably connected to the bar for enabling the nozzle opening tobe varied.

ALLAN ASHIWEAD TUNLEY.

